Vista - Virtual Machine Additions reduces me to 4-bit colour!

I'm very new to Virtual PC and setting up and installing a 32-bit XP Pro VPC
on my Vista 64-bit Ultimate machine was amazingly simple!

It looked great and I got it looking the way I wanted - Windows Classic
theme, no sounds etc. Not sure if you're supposed to install drivers on a VPC
or not but I was very happy with this - it's solely to test web designs in
IE6.

After wondering how I connect to the internet to view my sites I read I can
just use shared folders with the Additions. So I do this and make my web
design folder a share. Worked OK but after restarting XP in the VM I now have
S3 Trio 32/4 drivers limiting me to 4-bit colour! It's also very slow. I
tried downloading the nVidia drivers for XP but it won't let me install them.
I just want to go back to the pre-Additions install but with shared folders.
is there any fix for this?

I should have searched first!

Seems there are a couple of possible solutions:

Disable hardware virtualisation - not available to me!
Uninstall S3 drivers - they just auto re-install on restart!
Install SP3 - I was really hoping to keep the size of this VPC to a minimum
and avoiding this stuff...

Had to go with 3 in the end.